See the H&SEs recommended drop test for 'safe', non fragile roofing assemblies in action. 16mm multiwall polycarbonate glazing sheet fitted into standard glazing bars at 1000mm centres fails the test. Fitted into the Multi-Link-Panel NF 16mm multiwall passes with a 'B' designation. This demonstrates why 'roofing assemblies' and not individual products have to be tested. It is the patented fixing method in the Multi-Link-Panel NF that holds the multiwall glazing safely in place.